1. Field of the Invention
This invention relates to valves and is directed more particularly to plastic ball valves of the type typically used with plastic pipe in gas distribution lines.
2. Description of the Prior Art
The provision of plastic ball valves for use in plastic pipe, particularly in gas distribution systems, is well known. U.S. Pat. No. 4,047,275 issued Sep. 13, 1977 to Earl A. Bake, et al, for example, describes an all-plastic valve and a method for assembling the valve. The Bake et al valve includes a main body and two end sections which, with components assembled therein, are fused together to provide a valve body having conduits extending therefrom and adapted for connection to a plastic pipe.
In keeping with environmental concerns, it is deemed beneficial to reduce to the extent possible, and eliminate where possible, any leakage from such valves. Accordingly, there is need in the industry for a valve adapted for use underground in gas distribution system, as in the Bake et al valve, but improved with respect to the sealing means resident in the valve to prevent, or at least minimize, undesirable emissions.
It is also deemed beneficial to provide such a valve in which the number of parts is reduced and/or the number of major steps in assembling the valve is reduced.